Other Proposed Uses

Brewer’s yeast, also known as
Saccharomyces cerevisiae
, is commonly used in baking and the fermentation of beer; hence, the common name. Brewer’s yeast is rich in nutrients like
chromium
, B vitamins, protein,
selenium
,
potassium
,
iron
,
zinc
, and
magnesium
. It is the byproduct of beer brewing and can be grown on hops. Hops are the dried flowers that give beer its bitter taste. The yeast is separated from the beer after fermentation and processed. Aside from hops, the yeast can also be cultivated on other plants, like sugar beets.

Brewer’s yeast, along with its close cousin
Saccharomyces boulardii
, is considered a probiotic. Probiotics are foods or dietary supplements that contain organisms, like bacteria or yeast, which provide health benefits for humans. Along with brewer’s yeast, another example of a probiotic is yogurt with live and active bacteria cultures.

Bacteria and yeasts naturally live in our bodies, mainly in the digestive tract. Probiotics contain “good” bacteria or yeasts that keep our digestive tract functioning properly, as well as keeping the population of harmful or “bad” organisms low.
1
The probiotic activity of
S. boulardii
in particular has been studied in the treatment of a number of conditions including:
2,3,8

In addition to its probiotic benefits, Brewer’s yeast has been used as a protein supplement and is promoted as an energy and immunity enhancer.

This article covers both
S. cerevisiae
and
S boulardii
.

Sources

Brewer’s yeast is usually sold in the form of a powder, flakes, liquid, or tablets. It
can also be found as part of other food products, like fermented milks.
7

Therapeutic Dosages

For adults, brewer’s yeast can be taken at a dose of 1-2 tablespoons per day. The powder
form can be added to food or mixed with water or juice.
7

Probiotics, in general, should have several billion microorganisms per dose. This makes
it more likely that the bacteria or yeasts will grow in the gut.
3

A standard dose of
S. boulardii1
is 500 mg (milligrams) twice a day. This
provides around 3 x 10 10-colony-forming units per gram. If taken to prevent
antibiotic-associated diarrhea, for example, the yeast should be taken before and a few days
after using antibiotics. The same is true for traveler’s diarrhea.
1

Therapeutic Uses

The strongest evidence supporting the benefits of brewer’s yeast is for
diarrhea
. Some
studies have shown brewer’s yeast to be effective in preventing antibiotic-associated
diarrhea, as well as relapsing colitis caused by the bacterium
Clostridium difficile
.
S. boulardii
may fight this form of diarrhea by making enzymes
that counteract the effect of toxins produced by
C. difficile
.
2,3

Since brewer’s yeast is a rich source of the mineral chromium, it has been studied for
its ability to improve blood sugar control in patients with diabetes.
6

What Is the Scientific Evidence for Brewer’s Yeast?

Determining the effectiveness of brewer’s yeast, as well as other probiotics, is
hampered by the fact that many studies use combinations of differing bacterial and yeast
strains. This makes it difficult to know whether only one or all of the components are
needed for a beneficial effect. Nevertheless, a number of studies focusing only on
S.
boulardii
or
S. cerevisiae
have shown beneficial effects.

Diarrhea

Numerous studies have investigated the benefits of
S. boulardii5,12,13
in antibiotic-associated diarrhea and traveler's diarrhea in adults.

A mathematical analysis of ten randomized, controlled studies found
S.
boulardii5
to be effective for the prevention of antibiotic-associated diarrhea.

In a controlled, double-blind study involving 3,000 Austrian tourists traveling
through hot climates, researchers found that
S. boulardii13
started five days
before departure and continued through the duration of travel significantly reduced the
incidence of traveler’s diarrhea compared to placebo. The effectiveness was dependent on
the dose given and its preparation.

A systematic review of studies focusing on the effectiveness of
S. boulardii
in preventing
C.
difficile
infection (the bacteria that causes
antibiotic-associated diarrhea), found that the yeast may be effective in protecting
against reoccurring infections, but not necessarily first-time infections.
11

Other studies have also shown that
S. boulardii9,10
may reduce the
duration of diarrhea in children.

Helicobacter Pylori

Helicobacter pylori
, a common bacterium present
in the stomach and upper intestines of some people, is associated with an increased risk
of peptic ulcers. Treatment for
H. pylori
usually involves more than one antibiotic to suppress the
bacteria. While there is little evidence that
S. boulardii
can help treat
H. pylori
, it may effectively reduce
the side effects associated with standard treatment for this condition.

One clinical trial, for example, compared two groups of children aged 3-18 years
infected with the
H. pylori
bacteria. One group
was given medicines to treat the infection plus
S. boulardii
. The other group was given medicines plus
a placebo. The group who took
S. boulardii
with their medicines had fewer side effects compared to the
placebo group.
14
Side effects included bloating, taste problems, and nausea.

Cold and Flu

A large, randomized trial found a positive effect for brewer’s yeast in preventing
colds and seasonal influenza (flu). In the study, 116 adults who had received a flu shot
were given either 500 mg of a brewer’s yeast product called EpiCor or placebo for 12
weeks. Researchers found that those who received Epicor had fewer colds and flu. And those
on Epicor who did get a cold or flu were sick for a shorter length of time compared to
participants taking placebo.
4
Far more research is required before brewer’s
yeast can be routinely recommended for the prevention of colds and flu.

Safety Issues

Brewer’s yeast, along with other probiotics, is generally considered safe. Some people
may experience bloating or gas when taking probiotics.
1

Those who should practice caution when using probiotics include people who are severely
sick, have immune system issues, or those who have central venous catheters.
3

People allergic to yeast or who are more likely to have yeast infections should not take
brewer’s yeast. Also, people with
diabetes
should talk to their doctor before taking
brewer’s yeast, since it can interact with their medicines and cause lower than expected
blood sugar.
7

Always talk to a doctor before taking any supplement or medicine.

Interactions You Should Know About

People taking any of the medicines listed below should exercise caution when taking
brewer’s yeast:
7

Pain Medication

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.